I recently upgraded the Mini firmware to the newest version. But I wasn't aware at the time that the batteries needed to be upgraded. Now that I am aware, I am unable to upgrade my other two batteries (assuming that the one in the AC during the firmware upgrade did, in fact, upgrade). Should I be concerned? How can I do a firmware upgrade on the batteries? While the remote and AC are powered up and connected, I have checked on the firmware version multiple times and It doesn't offer to upgrade batteries. Thanks.